Roll forming, also spelled rollforming, is a continuous bending operation in which a long strip of sheet metal (typically coiled steel) is passed through sets of rolls mounted on consecutive stands, each set performing only an incremental part of the bend, until the desired cross-section profile is obtained. Roll forming is ideal for producing constant-profile parts with long lengths and in large quantities.
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate. There are many different metals that can be made into sheet metal, such as aluminum, brass, copper, steel, tin, nickel and titanium. Conventional sheet metals and alloys deform via the formation of dislocations, i.e., plastic work. For these conventional metals, sheet metal fabrication processes can mostly be placed into two categories—forming and cutting. Forming processes are those in which the applied force causes the material to plastically deform, but not to fail. So what one could be doing is one could be introducing plastic work into the alloy as one could form it into thinner and thinner sheets. So it is cold worked. Such processes are able to bend or stretch the sheet into the desired shape. Cutting processes are those in which the applied force causes the material to fail and separate, allowing the material to be cut or removed.
On the other hand, for a bulk-solidifying amorphous alloy (also referred to as bulk metallic glass (BMG)), the sheet forming processes of the conventional crystalline metals are generally not applicable as amorphous alloys do not deform by the formation of dislocations. They fail through the formation of shear bands, which are, in general, the sort of process that are not really desirable. Therefore, new methods for roll forming BMG feedstock are desirable.